The present invention relates to particles which are based on polylactones derived from polyhydroxycarboxylic acids and which readily disaggregate in an aqueous medium, and also to pulverulent compositions in which these particles are present and which can be used, in particular, for washing, cleaning and bleaching.
It is known from Belgian Pat. No. 830,603, filed June 25, 1975, to employ, in pulverulent compositions for washing, cleaning and bleaching, particles of polylactones derived from hydroxyacrylic acid polymers. These polylactones are intermolecular and intramolecular esters of .alpha.-hydroxyacrylic acid homopolymers and copolymers, are generally in the form of particles consisting exclusively of polylactones, and are usually insoluble in water. These polylactone particles are employed together with particles of a basic compound. In the abovementioned pulverulent compositions, the polylactones associated with a basic compound advantageously replace the hydroxycarboxylic acid polymers which themselves carry out, with a very substantially increased efficiency, the functions performed in the conventional compositions by alkali metal polyphosphates.
However, the polylactone particles used in accordance with the known process exhibit a serious disadvantage. The abovementioned pulverulent compositions are employed in an aqueous medium, and the polylactone particles slowly disaggregate in the medium and thus considerably slow down the washing, cleaning or bleaching process.